The 0-1 EPL match between Wolverhampton and Liverpool was blocked by an injury to goalkeeper Rui Patricio.
The Portuguese left the field on a stretcher in 101 minutes after he collided with defender Conor Coady in the 86th minute (who hit him on the head with his knee).
As a result, the game resumed.
As part of testing an additional concussion replacement, the Wolves were able to release goalkeeper John Ruddy despite Nuno Espírito Santo using all three substitutions.
This season Patricio has played 9 of his 29 EPL games with a clean sheet.